nutrients
Article
Trends of Adherence to the Mediterranean Dietary
Pattern in Northern Italy from 2010 to 2016
Alessandro Leone *
, Alberto Battezzati, Ramona De Amicis, Giulia De Carlo and Simona Bertoli
International Center for the Assessment of Nutritional Status (ICANS), Department of Food, Environmental and
Nutritional Sciences (DeFENS), University of Milan, Via Sandro Botticelli 21, 20133 Milan, Italy;
[email protected] (A.B.); [email protected] (R.D.A.); [email protected] (G.D.C.);
[email protected] (S.B.)
* Correspondence: [email protected]; Tel.: +39-0250316652
Received: 18 May 2017; Accepted: 4 July 2017; Published: 11 July 2017
Abstract: Little information is available on the trends of adherence to the Mediterranean dietary pattern
(MDP). This study investigates food consumption trends from 2010 to 2016 in subjects living in Northern
Italy. A cross-sectional study of 8584 subjects enrolled between January 2010 and December 2016
was conducted. Socio-demographic, nutrition and lifestyle characteristics were collected. A 14-item
questionnaire was used to evaluate adherence to MDP. Multivariable Poisson regression was used
to evaluate the trends of and the determinants for the adherence to MDP. The overall prevalence of
adherence to MDP was 14% and the trend remained constant over the six years. However, there was a
marked increase in nuts consumption and a slight one in white meat consumption. Furthermore, we
observed a decrease in the consumption of fruit, red meat, sweets and sugar-sweetened beverages and in
the use of soffritto. Finally, higher education, being older, married, physically active, and ex-smoker was
associated with greater adherence to MDP, whereas the prevalence of adherence was lower in the obese.
In conclusion, the consumption of some Mediterranean and non-Mediterranean food groups changed
over the six years. However, overall, the prevalence of adherence to MDP did not change. Additional
strategies promoting healthy dietary habits are needed.
Keywords: Mediterranean diet; determinants; prevalence; trends; food consumption; Italy
1. Introduction
The Mediterranean diet was defined as the traditional dietary pattern of people living in Greece,
Southern Italy, Spain and other countries of the Mediterranean basin [1]. It is characterized by a high
consumption of cereals, vegetables, fruits, nuts, legumes, seeds and olives, with olive oil as principal
source of added fat, along with high-to-moderate intakes of fish and seafood, moderate consumption
of eggs, poultry and dairy products (cheese and yogurt), low consumption of red meat and a moderate
intake of alcohol (mainly wine during meals) [1]. In 2010, this dietary pattern has been recognized as
an Intangible Cultural Heritage of Humanity by United Nations Educational, Scientific and Cultural
Organization (UNESCO).
After the Seven Countries Study [2], which observed low death rates for all-cause and coronary
heart disease in cohorts where olive oil was used as the main fat, numerous and increasing
epidemiological studies and trials have established the health benefits associated with adherence to the
Mediterranean dietary pattern (MDP), mainly in relation to reducing the risk of developing CVD [3],
metabolic syndrome [4], type 2 diabetes [5], cancer [6] and some neurodegenerative diseases [7]. More
recently, several prospective and cross-sectional studies have observed an inverse association between
the adherence to the MDP and the risk of mental diseases like depression [8] and eating disorders [9].
Despite these documented health benefits, there has been a rapid decline in MDP adherence in
recent decades [10]. Indeed, an early retrospective study noted this, especially in Mediterranean
Nutrients 2017, 9, 734; doi:10.3390/nu9070734
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populations, on comparing MDP adherence in the 2000–2003 period to that of 1961–1965 [11].
Subsequently, from 2005 to 2010, a deep decline in adherence to MDP was recorded in the population
of Southern Italy, with prevalence falling from over 30% to 18% [12]. A study conducted in Spain in
2008–2010 recorded that only 12% of subjects had dietary habits in accordance with MDP [13], while
a previous study in Northern Italy reported constant adherence to the MDP during the 1991–2006
period [14]. However, in this latter study, no information was given about the prevalence of adherence
to MDP. Moreover, since 2010, no study has investigated the trends of adherence to MDP. Therefore,
the aim of the present study was to investigate the trends of adherence to MDP from 2010 to 2016 in a
large cohort of subjects living in Northern Italy.
2. Materials and Methods
2.1. Study Design
We performed a cross-sectional study on 8584 consecutive adults who self-referred to the
International Center for the Assessment of Nutritional Status (ICANS, University of Milan) from
January 2010 to December 2016, in order to participate in a structured weight loss or weight maintenance
program. On the same day, they underwent a clinical examination, an anthropometric assessment and
a structured interview by trained dieticians to obtain information about marital status, educational
level, smoking and structured physical activity. Subjects who spent ≥2 h per week in any structured
physical activity were considered as active [15]. All the patients filled in a questionnaire to evaluate
MDP adherence [16]. Exclusion criteria were: age < 18, subjects undergoing medical nutritional therapy
for any condition or following any kind of weight loss dietary regimen in the last six months, subjects
with known problem of alcohol abuse, subjects diagnosed as having acute infective, neurological,
gastrointestinal, cardiac, renal and pulmonary failure, or who were unable to understand and fill in the
questionnaires. This study was conducted according to the guidelines laid down in the Declaration of
Helsinki and all procedures involving human subjects were approved by the Ethics Committee of the
University of Milan (23/16). Written informed consent was obtained from all subjects.
2.2. Anthropometric Measurements
Anthropometric measurements were made according to the conventional criteria and measuring
procedures proposed by Lohmann et al. [17]. Weight, to 100 g, was measured on a Column scale (Seca
700 balance, Seca Corporation, Hanover, MD, USA) with subjects wearing only light underwear and
an empty bladder. Height was measured to the nearest 0.1 cm using a vertical stadiometer (Seca 217
stable stadiometer, Seca Corporation, Hanover, MD, USA). Waist circumference (WC) was measured
midway between the lower rib margin and the superior anterior iliac spine taken to the nearest 0.5 cm,
and measured with a non-stretch tape applied horizontally.
2.3. Adherence to the Mediterranean Dietary Pattern
Adherence to MDP was evaluated using a validated 14-item questionnaire [16]. Schröder et al. [16]
found a good correlation (r = 0.52) and a good absolute agreement (intraclass correlation coefficient
(ICC) = 0.51) between the 14-item Mediterranean score (MedScore) and the Mediterranean score obtained
from a 136-item food frequency questionnaire, concluding that this short screener was a valid tool for a
rapid assessment of adherence to MDP. The MedScore was obtained from this questionnaire following the
guidelines of the Prevención con Dieta Mediterránea (PREDIMED) study group (www.predimed.es) with
some adaptation already used in previous studies [9,18–20]. Briefly, one point was attributed for each of
the following: (1) olive oil as the main cooking fat; (2) olive oil ≥ 4 tablespoons/day; (3) vegetables ≥
2 servings/day (≥1 portion raw or on salad); (4) fruit ≥ 3 servings/day; (5) red or processed meat < 1
serving/day; (6) butter or cream or margarine < 1/day; (7) sugar-sweetened beverages < 1/day; (8) wine
≥ 3 glasses/week; (9) legumes ≥ 3 servings/week; (10) fish/seafood ≥ 3 servings/week; (11) commercial
sweets and confectionery < 3/week; (12) nuts ≥ 1/week; (13) white more than red meats (yes) and;
Nutrients 2017, 9, 734
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(14) use of soffritto ≥ 2/week. Subjects with a MedScore ≥ 9 points were considered to have a dietary
pattern in accordance with the MDP [9,18–20].
2.4. Statistical Analysis
Most continuous variables had non-Gaussian distributions, and all are reported as 25th, 50th
and 75th percentiles. Discrete variables are reported as counts and percentages. A Poisson
working regression model (PWRM) with a robust 95% confidence interval was used to estimate
prevalence and prevalence ratios (PR) of adherence to MDP and to its individual components.
Uni- and multivariable PWRM were used to evaluate the association of adherence to MDP, and
individual components, with sex, age, body mass index (BMI), educational level, occupation, marital
status, smoking status, physical activity and year of recruitment. The outcome variables of all
models (adherence to MDP and to its individual components) were discrete (0 = no; 1 = yes).
The covariates were coded as follows: (i) sex (discrete, 0 = female; 1 = male); (ii) age (continuous, years);
(iii) BMI (continuous, kg/m2 ); (iv) educational level (discrete, 0 = ≤high school; 1 = >high school);
(v) occupation (discrete, 0 = unemployed/student/retired/housewife, 1 = worker); (vi) marital status
(discrete, 0 = single/widower; 1 = married/cohabiting); (vii) smoking status (discrete, 0 = non-smoker;
1 = smoker; 2 = ex-smoker); (viii) physical activity (discrete, 0 = no; 1 = yes) and (ix) year of recruitment
(ordinal, 0 = 2010; 1 = 2011; 2 = 2012; 3 = 2013; 4 = 2014; 5 = 2015; 6 = 2016). Prevalence ratios and
marginal probabilities were calculated from PWRM [21]. Tests of linear trend across increasing year of
recruitment were conducted treating the variable as a continuous variable. Uni- and multivariable
fractional polynomials (MFP) were used to test whether the relationships of continuous predictors
with the outcomes were non-linear [22,23]. Using this approach, no transformation or different
transformations of age and BMI were selected in function of the outcome of interest. However, as there
was only a modest gain in the linearity of continuous predictors when MFP were applied to the PWRM,
all continuous covariates were kept untransformed with the benefit of making the relationships more
understandable to a clinical audience [15]. Statistical analysis was performed using Stata 12.1 (Stata
Corporation, College Station, TX, USA).
3. Results
Overall characteristics of the recruited sample are reported in Table 1.
Table 1. General characteristics of the studied sample according to the year of recruitment.
2010 (n = 1251)
Age (years)
BMI (kg/m2 )
WC (cm)
MedScore
2012 (n = 1212)
2013 (n = 1242)
P50
P75
P25
P50
P75
P25
P50
P75
P25
P50
P75
37
25.6
85.3
5
45
28.7
95.1
7
55
32.2
105.5
8
38
25.4
85.5
6
46
28.7
95.0
7
55
32.3
105.5
8
38
25.4
86.6
5
47
28.6
96.2
7
56
32.5
106.0
8
37
25.2
86.0
5
45
28.3
95.7
7
55
32.4
106.6
8
2014 (n = 1192)
Age (years)
BMI (kg/m2 )
WC (cm)
MedScore
2011 (n = 1203)
P25
2015 (n = 1244)
2016 (n = 1240)
Total (n = 8584)
P25
P50
P75
P25
P50
P75
P25
P50
P75
P25
P50
P75
38
25.5
87.7
6
47
28.5
97.2
7
55
32.3
106.3
8
37
25.1
86.8
6
46
28.2
96.0
7
54
32.3
106.9
8
37
25.4
88.0
6
47
28.6
98.3
7
55
33.0
108.0
8
37
25.4
86.5
6
46
28.6
96.0
7
55
32.4
106.5
8
Abbreviation: P25 = 25th percentile; P50 = 50th percentile; P75 = 75th percentile; BMI = body mass index;
WC = waist circumference.
Socio-anagraphic, nutritional status and lifestyle characteristics of the sample are reported in
Table 2.
In the pool sample, 14% of subjects had a dietary pattern in accordance with MDP. Table 3 shows
the trends of and the determinants for the adherence to MDP and individual components expressed as
PRs, and the Supplementary Table S1 shows the corresponding predicted probabilities.
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Table 2. Socio-anagraphic, nutritional status and lifestyle characteristics of the sample according to the year of recruitment.
2010
2011
2012
2013
2014
2015
2016
Total
N
%
N
%
N
%
N
%
N
%
N
%
N
%
N
%
877
374
70.1
29.9
848
355
70.5
29.5
862
350
71.1
28.9
910
332
73.3
26.7
846
346
71
29
880
364
70.7
29.3
886
354
71.5
28.5
6109
2475
71.2
28.8
16
115
280
355
271
166
48
1.3
9.2
22.4
28.4
21.7
13.3
3.8
14
106
248
360
269
169
37
1.2
8.8
20.6
29.9
22.4
14
3.1
17
112
224
373
287
156
43
1.4
9.2
18.5
30.8
23.7
12.9
3.5
18
123
262
371
266
157
45
1.4
9.9
21.1
29.9
21.4
12.6
3.6
14
101
232
350
289
156
50
1.2
8.5
19.5
29.4
24.2
13.1
4.2
21
110
243
379
307
133
51
1.7
8.8
19.5
30.5
24.7
10.7
4.1
20
122
234
355
309
150
50
1.6
9.8
18.9
28.6
24.9
12.1
4.0
120
789
1723
2543
1998
1087
324
1.4
9.2
20.1
29.6
23.3
12.7
3.8
256
499
342
154
20.5
39.9
27.3
12.3
268
469
306
160
22.3
39
25.4
13.3
262
471
304
175
21.6
38.9
25.1
14.4
291
458
329
164
23.4
36.9
26.5
13.2
250
477
311
154
21
40
26.1
12.9
307
462
309
166
24.7
37.1
24.8
13.3
271
461
305
203
21.9
37.2
24.6
16.4
1905
3297
2206
1176
22.2
38.4
25.7
13.7
757
494
60.5
39.5
787
416
65.4
34.6
758
454
62.5
37.5
727
515
58.5
41.5
677
515
56.8
43.2
671
573
53.9
46.1
678
562
54.7
45.3
5055
3529
58.9
41.1
256
995
20.5
79.5
280
923
23.3
76.7
271
941
22.4
77.6
295
947
23.8
76.2
235
957
19.7
80.3
242
1002
19.5
80.5
265
975
21.4
78.6
1844
6740
21.5
78.5
546
705
43.6
56.4
531
672
44.1
55.9
564
648
46.5
53.5
598
644
48.1
51.9
551
641
46.2
53.8
595
649
47.8
52.2
594
646
47.9
52.1
3979
4605
46.4
53.6
667
251
333
53.3
20.1
26.6
639
252
312
53.1
20.9
25.9
661
258
293
54.5
21.3
24.2
680
237
325
54.8
19.1
26.2
617
246
329
51.8
20.6
27.6
631
357
256
50.7
28.7
20.6
736
313
191
59.4
25.2
15.4
4631
1914
2039
53.9
22.3
23.8
715
536
57.2
42.8
749
454
62.3
37.7
761
451
62.8
37.2
712
530
57.3
42.7
638
554
53.5
46.5
606
638
48.7
51.3
663
577
53.5
46.5
4844
3740
56.4
43.6
85.6
14.4
1040
172
85.8
14.2
1077
165
86.7
13.3
1023
169
85.8
14.2
1057
187
85.0
15.0
1062
178
85.6
14.4
7384
1200
86.0
14.0
Sex
Female
Male
Age Categories
18–19 years
20–29 years
30–39 years
40–49 years
50–59 years
60–69 years
≥70 years
BMI Classes
Normal weight
Overweight
Obesity 1 class
Obesity 2 and 3 class
Education
Low degree
High degree
Occupation
Unworker
Worker
Marital Status
Single
Married
Smoking
Non-smoker
Smoker
Ex-smoker
Physical Activity
No
Yes
Adherence to the Mediterranean Dietary Pattern
No
Yes
1095
156
87.5
12.5
1030
173
Nutrients 2017, 9, 734
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Table 3. Trends of and determinants for adherence to the Mediterranean dietary pattern (MDP) and its individual food-items.
MDP (Yes)
Olive Oil
(Yes)
Olive Oil
(≥4 sp/Day)
Vegetable
(≥2 s/Day)
Fruits
(≥3 u/Day)
Red Meat
(<1 s/Day)
Animal Fats
(<1 s/Day)
Sweetened
Beverages
(<1 gl/Day)
Wine
(≥3 gl/Week)
Legumes
(≥3 s/Week)
Fish
(≥3 s/Week)
Sweets
(<3 t/Week)
Nuts
(≥1 s/Week)
White
Meat (Yes)
Soffrito
(≥2 t/Week)
Ref.
1.18
[0.97,1.43]
1.16
[0.96,1.42]
1.07
[0.87,1.30]
1.10
[0.90,1.34]
1.18
[0.97,1.44]
1.16
[0.95,1.41]
0.292
Ref.
1.00
[0.99,1.02]
1.00
[0.98,1.01]
1.00
[0.99,1.01]
1.00
[0.99,1.02]
1.00
[0.99,1.01]
1.01
[0.99,1.02]
0.455
Ref.
1.37 ***
[1.22,1.53]
1.49 ***
[1.33,1.67]
1.44 ***
[1.28,1.61]
1.19 **
[1.06,1.34]
1.19 **
[1.06,1.34]
1.18**
[1.04,1.33]
0.761
Ref.
1.07
[1.00,1.15]
0.96
[0.89,1.03]
0.98
[0.91,1.06]
1.06
[0.98,1.13]
1.06
[0.99,1.14]
1.04
[0.97,1.12]
0.142
Ref.
0.89
[0.74,1.08]
0.75 **
[0.61,0.92]
0.81 *
[0.67,0.98]
0.65 ***
[0.53,0.80]
0.65 ***
[0.53,0.80]
0.60 ***
[0.49,0.74]
<0.001
Ref.
1.02
[0.96,1.08]
1.05
[1.00,1.11]
1.05
[1.00,1.11]
1.01
[0.95,1.06]
1.05
[1.00,1.11]
1.09 ***
[1.04,1.15]
0.005
Ref.
1.00
[0.99,1.01]
1.00
[0.99,1.02]
1.01
[0.99,1.02]
1.01
[0.99,1.02]
1.00
[0.99,1.02]
1.00
[0.99,1.02]
0.390
Ref.
1.02
[0.99,1.06]
1.00
[0.97,1.04]
1.02
[0.99,1.06]
1.03
[0.99,1.07]
1.05 **
[1.02,1.09]
1.06 ***
[1.03,1.10]
<0.001
Ref.
1.09
[0.97,1.22]
1.18 **
[1.05,1.32]
1.10
[0.98,1.24]
1.12
[1.00,1.26]
1.09
[0.97,1.22]
1.08
[0.96,1.22]
0.376
Ref.
1.02
[0.72,1.44]
0.84
[0.59,1.22]
0.71
[0.48,1.03]
1.04
[0.73,1.46]
0.90
[0.63,1.28]
0.96
[0.68,1.36]
0.818
Ref.
0.83
[0.65,1.07]
0.77 *
[0.60,1.00]
0.84
[0.66,1.07]
0.87
[0.68,1.11]
0.82
[0.64,1.04]
0.93
[0.73,1.18]
0.724
Ref.
1.05
[0.97,1.13]
1.09 *
[1.02,1.17]
1.05
[0.98,1.13]
1.11 **
[1.03,1.19]
1.09 *
[1.01,1.17]
1.07
[1.00,1.16]
0.026
Ref.
1.28 *
[1.02,1.61]
1.55 ***
[1.25,1.92]
1.81 ***
[1.47,2.23]
2.16 ***
[1.76,2.64]
2.53 ***
[2.08,3.08]
2.75 ***
[2.27,3.34]
<0.001
Ref.
1.01
[0.94,1.08]
1.03
[0.96,1.10]
1.09 **
[1.03,1.17]
1.10 **
[1.03,1.18]
1.07 *
[1.01,1.15]
1.10 **
[1.03,1.17]
<0.001
Ref.
0.95
[0.89,1.02]
0.66 ***
[0.60,0.72]
0.56 ***
[0.51,0.62]
0.59 ***
[0.54,0.65]
0.61 ***
[0.55,0.66]
0.60 ***
[0.55,0.66]
<0.001
Ref.
0.99
[0.88,1.11]
1.03 ***
[1.03,1.04]
0.98 ***
[0.97,0.99]
Ref.
0.99
[0.99,1.00]
1.00 ***
[1.00,1.00]
1.00
[1.00,1.00]
Ref.
0.83 ***
[0.77,0.88]
1.00 *
[0.99,1.00]
1.01 ***
[1.00,1.02]
Ref.
0.84 ***
[0.80,0.88]
1.01 ***
[1.01,1.01]
1.00
[0.99,1.00]
Ref.
0.89
[0.78,1.01]
1.04 ***
[1.03,1.04]
1.01
[1.00,1.02]
Ref.
0.98
[0.95,1.01]
1.01 ***
[1.01,1.01]
0.99 ***
[0.98,0.99]
Ref.
1.00
[0.99,1.01]
1.00
[1.00,1.00]
1.00
[1.00,1.00]
Ref.
0.95 ***
[0.93,0.97]
1.00 ***
[1.00,1.00]
1.00 **
[1.00,1.00]
Ref.
1.89 ***
[1.77,2.01]
1.02 ***
[1.02,1.02]
0.97 ***
[0.97,0.98]
Ref.
1.56 ***
[1.27,1.92]
1.02 ***
[1.01,1.02]
0.99
[0.97,1.01]
Ref.
0.82 *
[0.70,0.97]
1.01 ***
[1.01,1.02]
0.99
[0.97,1.00]
Ref.
1.04
[1.00,1.09]
1.00 ***
[1.00,1.01]
1.00
[0.99,1.00]
Ref.
0.98
[0.88,1.08]
1.03 ***
[1.02,1.03]
0.97 ***
[0.96,0.98]
Ref.
0.83 ***
[0.80,0.87]
1.00 ***
[1.00,1.01]
1.00
[1.00,1.01]
Ref.
1.12 ***
[1.06,1.19]
1.00 *
[1.00,1.00]
1.01 ***
[1.01,1.02]
Ref.
1.13 *
[1.01,1.26]
Ref.
1.01 *
[1.00,1.01]
Ref.
1.01
[0.95,1.07]
Ref.
1.09 ***
[1.05,1.13]
Ref.
1.06
[0.94,1.19]
Ref.
1.02
[0.99,1.05]
Ref.
1.01
[1.00,1.01]
Ref.
1.05 ***
[1.03,1.07]
Ref.
1.21 ***
[1.14,1.29]
Ref.
1.51 ***
[1.23,1.84]
Ref.
1.31 ***
[1.14,1.51]
Ref.
0.99
[0.95,1.03]
Ref.
1.05
[0.96,1.15]
Ref.
0.87 ***
[0.84,0.90]
Ref.
1.01
[0.96,1.07]
Ref.
0.88
[0.77,1.00]
Ref.
1.02 ***
[1.01,1.03]
Ref.
1.05
[0.97,1.13]
Ref.
0.90 ***
[0.86,0.94]
Ref.
0.79 **
[0.68,0.92]
Ref.
0.99
[0.95,1.03]
Ref.
1.01
[1.00,1.01]
Ref.
0.97 *
[0.95,1.00]
Ref.
1.06
[0.98,1.14]
Ref.
0.85
[0.66,1.09]
Ref.
1.03
[0.86,1.23]
Ref.
0.84 ***
[0.80,0.87]
Ref.
1.07
[0.95,1.20]
Ref.
0.96 *
[0.92,1.00]
Ref.
0.95
[0.89,1.01]
Ref.
1.15 *
[1.03,1.28]
Ref.
1.00
[1.00,1.01]
Ref.
1.11 **
[1.04,1.18]
Ref.
1.04 *
[1.00,1.09]
Ref.
1.00
[0.89,1.12]
Ref.
0.95 ***
[0.92,0.98]
Ref.
0.99
[0.99,1.00]
Ref.
1.03 **
[1.01,1.05]
Ref.
1.02
[0.95,1.09]
Ref.
0.79 *
[0.65,0.97]
Ref.
0.84 *
[0.73,0.96]
Ref.
1.02
[0.98,1.07]
Ref.
0.91
[0.83,1.00]
Ref.
1.01
[0.98,1.05]
Ref.
1.21 ***
[1.15,1.28]
Ref.
1.03
[0.90,1.19]
1.22 **
[1.08,1.38]
Ref.
1.00
[0.99,1.01]
1.01 *
[1.00,1.02]
Ref.
1.13 **
[1.05,1.21]
1.16 ***
[1.08,1.24]
Ref.
0.96
[0.91,1.01]
1.02
[0.98,1.07]
Ref.
0.76 ***
[0.65,0.89]
0.84 **
[0.73,0.96]
Ref.
0.97
[0.93,1.00]
1.01
[0.98,1.05]
Ref.
1.00
[0.99,1.01]
1.00
[1.00,1.01]
Ref.
0.98
[0.96,1.00]
1.01
[0.98,1.03]
Ref.
1.44 ***
[1.33,1.55]
1.39 ***
[1.29,1.49]
Ref.
0.95
[0.74,1.22]
0.90
[0.70,1.14]
Ref.
0.89
[0.74,1.06]
1.12
[0.95,1.32]
Ref.
1.09 ***
[1.04,1.14]
1.10 ***
[1.05,1.15]
Ref.
0.94
[0.84,1.06]
1.18 **
[1.06,1.31]
Ref.
0.92 ***
[0.88,0.96]
0.94 **
[0.90,0.98]
Ref.
1.02
[0.96,1.09]
1.03
[0.97,1.09]
Ref.
1.37 ***
[1.23,1.52]
Ref.
1.00
[0.99,1.01]
Ref.
0.92 **
[0.86,0.97]
Ref.
1.18 ***
[1.14,1.23]
Ref.
1.16 *
[1.03,1.30]
Ref.
1.06 ***
[1.03,1.10]
Ref.
1.01
[1.00,1.01]
Ref.
1.06 ***
[1.04,1.07]
Ref.
1.02
[0.96,1.09]
Ref.
1.08
[0.88,1.32]
Ref.
1.46 ***
[1.27,1.68]
Ref.
1.10 ***
[1.06,1.15]
Ref.
1.32 ***
[1.21,1.45]
Ref.
1.09 ***
[1.06,1.13]
Ref.
0.92 **
[0.88,0.97]
Year
2010
2011
2012
2013
2014
2015
2016
P for trend
Sex
Women
Men
Age (Years)
BMI (kg/m2 )
Education
Low level
High level
Work
Non-worker
Worker
Marital status
Single
Married
Smoking
Non-smoker
Smoker
Ex-smoker
Physical activity
No
Yes
Values are prevalence ratios (PR) with robust 95% confidence intervals obtained from a multivariable Poisson working regression model (PWRM). Abbreviations: sp = spoons; s = servings;
u = units; gl = glass; t = times, Ref = reference category. * p < 0.05, ** p < 0.01, *** p < 0.001.
Nutrients 2017, 9, 734
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We observed an increment in the consumption of nuts (p for trend < 0.001) and white meat
(p for trend < 0.001) and a decrement in the consumption of fruit (p for trend < 0.001), red meat
(p for trend = 0.005), sweets (p for trend = 0.026), sugar-sweetened beverages (p for trend < 0.001) and
use of soffritto (p for trend < 0.001). The consumption of olive oil was higher during the 2011–2016
period, compared to 2010, but the linear trend was not significant (p for trend = 0.565). The adherence
to MDP did not change during the period of interest.
With regard to factors associated with the adherence to the MDP, we found that age (PR = 1.03,
95% CI: 1.03–1.04; for each 1-year increase), having a higher education (PR = 1.13, 95% CI: 1.01–1.26),
being married (PR = 1.15, 95% CI: 1.03–1.28), ex-smoker (PR = 1.22, 95% CI: 1.08–1.38) and physically
active (PR = 1.37, 95% CI: 1.23–1.52) were directly associated with the prevalence of adherence to the
MDP. On the contrary, BMI (PR = 0.98, 95% CI: 0.97–0.99; for each 1-kg/m2 increase) was inversely
associated with the prevalence of adherence to the MDP. Sex and having a job were not associated with
the prevalence of adherence to MDP, although this latter was almost significant.
Supplementary Figure S1 plots the prevalence of adherence to MDP and individual components
estimated from the PWRM as a function of age and BMI. It can be seen that the adherence to MDP
increased with increasing age and decreased with increasing BMI levels.
4. Discussion
In this study, we evaluated the trends of adherence to MDP and the consumption of individual food
groups during the period 2010–2016. We found that in Northern Italy, only 14% of the subjects had a
dietary pattern consistent with MDP, and this did not change over the six years. However, the consumption
of some Mediterranean and non-Mediterranean food groups changed during these years. We observed a
marked increase in the consumption of nuts and a slight one of white meat consumption. On the other
hand, there was a decrease in the consumption of fruit, sweets and sugar-sweetened beverages and in
the use of soffritto. Moreover, we found that age, nutritional status, having higher education and being
married, an ex-smoker and physically active were factors associated with better adherence to MDP.
Despite its health benefits, adherence to MDP has declined in the last decades. Indeed,
da Silva et al. [11] found a decrease in the level of adherence to MDP in the period 2000–2003 compared
to 1961–1965. This was more evident among subjects of Mediterranean countries. Bonaccio at el. [12]
recorded a deep decline in adherence to MDP, the prevalence falling from over 30% to 18% among
subjects included in the Molisani study during the period 2005–2010. Ecological studies have reported a
substantial departure from MDP all over Europe, but this is more evident in Mediterranean countries that
have experienced a “westernisation” process of food habits [24]. Furthermore, the increasing cost of many
key-foods of the Mediterranean diet has been proposed as a factor, driving people to give up this eating
pattern in favour of less expensive, energy-dense foods that typically have lower nutritional quality [25].
Our study, started in 2010, shows that the food pattern of only 14% of individuals was in accordance with
MDP, and the trend remained constant over the six years. The prevalence of adherence was slightly lower
than that recorded in 2010 in Southern Italy [12], and slightly higher than the prevalence of adherence
reported in Spain in 2008–2010. However, despite these little discrepancies between regions and countries,
presumably because of the different food cultures, and the different index used for defining MDP, the
overall prevalence was low. This highlights the importance of outreach interventions that promote the
health benefits of following a dietary pattern consistent with MDP.
Our study also shows the trends of consumption of individual Mediterranean and
non-Mediterranean food groups. Indeed, even though adherence to MDP did not change over the
six years, the consumption of some foods changed. Indeed, we recorded a strong increase in nuts
consumption, and hypothesize that this was due to the dissemination of results of recent trials and
observational cohorts suggesting a lower risk of disease associated with the consumption of nuts [26].
In addition to nuts consumption, we also observed a slight, but positive increase in the consumption
of white meat with a concomitant decrease in that of red meat. This could be a consequence of both the
economic crisis, which has led people to prefer, for price reasons, white meat rather than red, and of
Nutrients 2017, 9, 734
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the World Health Organization (WHO) recommendation to reduce the consumption of meat products.
Also positive is the slight decrease recorded for the consumption of sugar-sweetened beverages and
sweets. However, we also registered a decrease in the consumption of fruit and the use of soffritto, this
latter presumably because of the little time dedicated to the food preparation.
Consistently with some [27], but not all [12,13,28], previous findings, we did not find any sex
difference in MDP adherence. A possible explanation could be that, differently from the past, men
now tend to participate in food purchasing and meal preparation.
With regard to age, the older subjects reported a higher consumption of Mediterranean food,
tending to avoid non-Mediterranean foods, while the younger ones did the opposite, the only exception
being their use of olive oil and soffritto. Such dietary habits led to the older groups having a
higher adherence to MDP than the younger. The prevalence values ranged from nearly 0% for
the younger subjects to around 30–40% for the older. It is possible that the older subjects simply
maintained traditional dietary habits acquired in infancy, thus remaining less affected by the process
of diet-westernization, while young people tend to be more willing to accept food from other cultures.
Therefore, our results support the hypothesis of a departure, also in Northern Italy, from the MDP.
Concerning nutritional status, adherence to MDP decreased with increasing BMI. Indeed, lower
BMI was associated with greater wine and nuts consumption, whereas a higher BMI was associated
with a greater consumption of red meat and sugar-sweetened beverages, and also of the use of olive
oil and soffritto. The inverse association between adherence to the Mediterranean diet and obesity
has been reported by several cross-sectional [18] and longitudinal studies [29]. Similarly, a high
consumption of meat and processed meat [30], as well as sugar-sweetened beverages [31], has been
associated with an increased risk of obesity. The thorniest association is that of olive oil and risk of
obesity. Observational and intervention trials have consistently shown that a Mediterranean diet rich in
olive oil does not contribute to obesity, and may actually help curb it [32]. Indeed, a PREDIMED study
showed that an olive oil-rich diet was effective in the prevention of weight gain [33]. Independently
of the Mediterranean diet, few data are available on the role of olive oil in preventing or managing
obesity [32]. In a previous cross-sectional study, we found that olive oil consumption was associated
with a higher prevalence of obesity and greater abdominal visceral adipose thickness [18]. In fact,
the obese subjects in our study had a lower MDP adherence, therefore, it is possible that high olive
oil consumption associated with dietary habits not representative of MDP could increase the risk of
developing obesity.
Our results suggest that being married, or cohabiting, increases MDP adherence, a result that
agrees with previous investigations [28]. It also agrees with the recommendation that people eat
together around a table, as sharing food in the company of family and friends represents social support
and gives a sense of community; furthermore, the pleasure associated with the conviviality of meals
can affect food behaviour positively, and in turn, health status [34].
Our study has shown that adherence to MDP increased with educational level, a finding consistent
with previous investigations [13]. In fact, it is quite plausible that those who have a higher educational
level are more aware of the role of nutrition on health status.
Consistently with previous studies, the ex-smokers had a higher adherence to MDP [13,28].
Indeed, ex-smokers are more likely to make positive decisions concerning their health and, as previous
studies have suggested, they are more health-conscious and have a responsible profile [35].
Physical activity during leisure time was positively associated with adherence to MDP. These
results are similar to those of previous investigations [13,28] and suggest that those who practice
physical activity are more health conscious and probably more aware of the role of nutrition on health
status, body composition and physical performance.
The first strength of our study is that, to the best of our knowledge, it is the first study to investigate
the trends of adherence to MDP in Northern Italy since the last study published in 2010. Moreover,
the large sample size has ensured more accurate estimates, as can be seen by the restricted confidence
intervals. In addition, we used a validated questionnaire, previously used in the PREDIMED trial,
Nutrients 2017, 9, 734
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for defining the accordance to MDP. However, we could not evaluate the individual amounts of each
food or the macro and micro-nutrient intake, the first limitation of our study. The second is that
we used a cross-sectional design, which did not allow us to evaluate the intra-person changes in
food consumption and the cause–effect relationship. Moreover, the recruitment of different people
every year can theoretically be a further explanation of our results. However, we observed similar
socio-demographic, nutritional and lifestyle characteristics of subjects according to year of recruitment,
and, therefore, we do not have reason to think that the recruitment has affected our findings. The third
is that the enrolled subjects were seeking weight loss or a maintenance programme, which might
affect the general applicability of our findings to other groups or populations. The fourth limitation is
that, although in this study, during the time-period of six years, we have found some increments or
decrements in the consumption of several foods, we cannot rule out that some dietary habits can take
longer to be modified. Therefore, the long-term evaluation of the food consumption trends is needed
to confirm these results. The fifth is the lack of model adjustment for individual income; however,
we were able to adjust for education and occupation, thus reflecting the socioeconomic status of the
recruited subjects. The sixth is that we considered only leisure physical activity, without considering
the physical activity at work. Finally, as in any observational study, potential residual confounding
cannot be ruled out.
5. Conclusions
In conclusion, food consumption is in constant flux, undergoing continuous and constant
mutation, presumably in response to globalization processes, economic conditions, and also to the
dissemination of scientific research results. Some of these changes have led to an improvement in diet
quality, others to its impoverishment. So much so that, overall, the prevalence of adherence to MDP
did not change over the six studied years, remaining constant low. As dietary habits have an impact on
the risk of chronic diseases, these results have implications for public health, as this departure from the
MDP for a more Western dietary pattern may increase the risk of disease. Therefore, further strategies
are needed to promote healthy dietary habits, especially among young subjects and individuals at
risk of poor diet quality and, therefore, preserving present-day MDP knowledge for younger and
future generations.
Supplementary Materials: The following are available online at www.mdpi.com/2072-6643/9/7/734/s1, Figure
S1: Marginal probabilities of adherence to the Mediterranean dietary pattern and its individual components as a
function of age and nutritional status, Table S1: Estimated probabilities of adherence to the Mediterranean dietary
pattern and individual components for each factor.
Acknowledgments: We wish to thank the ICANS research staff and especially Chiara Lessa, Lidia Lewandowski
and Diana Osio for their help during this study. The study was supported by ICANS internal grants.
Author Contributions: A.L., A.B. and S.B. conceived and designed the experiments; A.L., R.D.A., G.D.C.
performed the experiments; A.L. analyzed the data; A.L. wrote the paper.
Conflicts of Interest: The authors declare no conflict of interest.
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